Situated on the Prosna river in the southeastern part of Greater Poland, the city forms a conurbation with the nearby towns of Ostrów Wielkopolski and Nowe Skalmierzyce.

It has served as an important regional center in Poland since the Middle Ages as a provincial capital and notable royal city.

It is the cultural, scientific, educational and administrative center of the eastern and southern Greater Poland region, and the seat of Roman Catholic Diocese of Kalisz.

It was a unique protective privilege for Jews during their persecution in Western Europe, which in the following centuries made Poland the destination of Jewish migration from other countries.

In 1282 the city laws were confirmed by Przemysł II of Poland, and in 1314 it was made the capital of the Kalisz Voivodeship by King Ladislaus the Short.

Because of its strategic location, King Casimir III the Great signed a peace treaty with the Teutonic Order there in 1343.

As a royal city, Kalisz managed to defend many of its initial privileges, and in 1426 a new town hall was built.

The economic development of the area was aided by a large number of Protestant Czech Brothers, who settled in and around Kalisz after being expelled from Bohemia in 1620.

[11] After the successful Greater Poland uprising of 1806, it was regained by Poles and became a provincial capital within the short-lived Duchy of Warsaw.

[14] With the outbreak of World War I, the proximity of the border proved disastrous for Kalisz; it was one of the first cities destroyed in 1914.

In revenge for resistance, the Wehrmacht carried out massacres of Polish defenders, who were executed both in the city and in the nearby settlement of Winiary (today, a district of Kalisz).

[20] In November 1939, the Einsatzgruppe VI Nazi paramilitary killing squad murdered 41 Poles at the local Jewish cemetery; among the victims was pre-war Polish mayor of Kalisz, Ignacy Bujnicki.

[21] In April and May 1940, many Poles arrested in the region, especially teachers, were imprisoned in the local prison, and afterwards deported to the Mauthausen and Dachau concentration camps, where they were murdered.

[23] The children were given new German names and surnames, and were punished for any use of the Polish language, even with death (e.g., a 14-year-old boy Zygmunt Światłowski [pl] was murdered).

[23] After their stay in the camp, the children were deported to Germany; only some returned to Poland after the war, while the fate of many remains unknown to this day.

In 1976, the city limits were greatly expanded by the incorporation of the surrounding settlements of Majków, Nosków, Piwonice and Szczypiorno as new districts.

[25] The Polish anti-communist resistance Movement for Defence of Human and Civic Rights issued independent underground press in the city.

[26] In August 1980, employees of local factories joined the nationwide anti-communist strikes,[27] which led to the foundation of the Solidarity organization, which played a central role in the end of communist rule in Poland.

It has the Winiary (part of the Nestlé group) and Colian food processing plants and the Big Star jeans factory.

The Andruty kaliskie wafers originated in Kalisz, and are the most well-known traditional food from the city in Poland.

[42] The district of Szczypiorno, as the place of pioneering games of handball in Poland, is the namesake for szczypiorniak, the Polish name of the sport.

Notable sports teams include: Kalisz is also the location of Kaliskie Towarzystwo Wioślarskie [pl], one of the oldest Polish rowing clubs, founded in 1894.